The public is being asked to make submissions on the topic during the Central Otago District Council draft annual plan consultation.
Trust chairwoman Kate Wilson, of Middlemarch, said the trust had not made a submission on the underpass before, but the issue of cyclists crossing SH8 at Clyde had been raised by trail operators and users, motivating the trust to become involved.
''We want to enable the district council to put it [the construction of an underpass] back on the agenda by saying a lot of people want it. We are encouraging the public to support it and encouraging them to submit on the subject in the annual plan,'' Mrs Wilson said.
Reasons for an underpass included safety of trail users and school pupils crossing the road, and current potential loss of economic benefits for Clyde, as the trail was on the opposite side of the highway to the town.
Mrs Wilson said the trust was aware the idea had stalled due to funding issues.
Council roading manager Julie Muir said the road was a state highway and therefore the responsibility of the New Zealand Transport Authority (NZTA).
A report to the council had previously said funding an underpass was not an NZTA priority.
The council would welcome support from groups interested in funding construction, Ms Muir said.
Mrs Wilson suggested some of the $8 million granted to New Zealand Cycle Trail Great Rides by the Government in late February for maintenance could be put towards an underpass, but could not say if the trust would be involved.
Clyde Primary School principal Doug White said the head of the school's Parent Teacher Association was ready to ''kick the issue along'' from a child safety point of view, with support from people in the area.
Olivers owner-operator David Ritchie said the community would get behind efforts to raise funds for an underpass, and urged people to make submissions on the matter.
Both men suggested other examples of underpasses built on NZTA land should be used as references for cost and procedure.
Submissions to the draft annual plan closes at 5pm on May 1.
